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प्रश्न
Molecules in air in the atmosphere are attracted by gravitational force of the earth. Explain why all of them do not fall into the earth just like an apple falling from a tree.
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उत्तर
Air molecules in the atmosphere are attracted by the gravitational force of the earth but they do not fall into the earth due to the reason that the molecules in air have some random motion due to temperature, so their resultant motion is not exactly the vertically downward direction.
But in the case of apples, only vertical motion dominates because of being heavier than air molecules. But due to gravity, the density of air is more near to the earth than the density as we go up.
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संबंधित प्रश्न
Write the formula to find the magnitude of the gravitational force between the earth and an object on the surface of the earth.
Choose the correct alternative:
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A thin spherical shell having uniform density is cut in two parts by a plane and kept separated as shown in the following figure. The point A is the centre of the plane section of the first part and B is the centre of the plane section of the second part. Show that the gravitational field at A due to the first part is equal in magnitude to the gravitational field at B due to the second part.

State whether the gravitational force between two masses is attractive or repulsive ?
All objects in the universe attract each other along the line joining their________.
Where will you weigh more: at the centre of the earth or at the surface of the earth?
A force can produce ________, In an object at rest. It can __________ an object and change its __________ of motion.
Why does a ball moving on a table top eventually stops?
The value of universal gravitational constant (G) in the SI unit is ______.
The ______ force is much weaker than other forces in nature.
Choose the wrong option.
If the law of gravitation, instead of being inverse-square law, becomes an inverse-cube law- ______.
- planets will not have elliptic orbits.
- circular orbits of planets is not possible.
- projectile motion of a stone thrown by hand on the surface of the earth will be approximately parabolic.
- there will be no gravitational force inside a spherical shell of uniform density.
Shown are several curves (Figure). Explain with reason, which ones amongst them can be possible trajectories traced by a projectile (neglect air friction).
Newton formulated the Universal Law of Gravitation by combining the ideas of which two scientists with his own Laws of Motion?
